More than 100,000 Americans have died of drug overdoses over a year-long period during the Covid-19 pandemic.

It is the highest yearly death toll from drugs ever recorded in the US.

Data from the Centers for Disease Control and Prevention shows that overdose deaths rose 28.5% in the 12 months ending this past April.

Experts believe that overdoses likely spiked because of the psychological toll of the pandemic and more synthetic opioids like fentanyl in the supply.

Overdoses rose in all but four of 50 US states.

Using data from death certificates, the CDC estimates that 100,306 people between April 2020 and April 2021, compared to 78,056 deaths reported the year prior.

Katherine Keyes, a drug abuse expert and associate professor of epidemiology at Columbia University, told the BBC that while overdose deaths have been rising "exponentially" over the last several years, the pandemic "added fuel to that fire".

"The data that is available indicates that there were more people using drugs alone, which we know is a risk factor for overdose," she explained. "There was also a decrease in access to services that might support overdose prevention, harm reduction, treatment and recovery."

The number of deaths from drugs has now surpassed those from guns, car crashes and the flu.

The highest increase in overdose deaths was recorded in Vermont, where the number of fatalities rose 70% to 209. Vermont was followed by West Virginia (62%) and Kentucky (55%).

Ms Keyes said that the rise of synthetic opioids - particularly fentanyl - are "among the most central contributors" to the rise in overdose deaths. Users of other drugs, such as cocaine or methamphetamine, are increasingly testing positive for fentanyl.

"It's kind of a moving epidemic that was really concentrated on people who primarily used opioids such as heroin, but now is kind of spreading out into people who are using other drugs as well," she added. "That really accelerates the overdose deaths that we're seeing to a broader range of drug users."

Shannon Monnat, the director of the Lerner Center for Public Health Promotion at Syracuse University, said that the overdose deaths are "an American tragedy, and it is preventable".

"Even after Covid is over, overdoses will likely continue to increase," she said. "We have to attack this crisis from multiple angles."

Among the possible solutions, she said, are fentanyl test strips and supervised consumption sites where users can be monitored and connected to recovery and healthcare services.

"But beyond this, we need to recognise that the increase in drug use disorders over the past 20 to 30 years is a symptom of much larger social and economic problems," Ms Monnat added.

"Ultimately, solutions to combat our drug overdose crisis will only be effective if they address the long-term social and economic determinants that are at the foundation of the crisis."